Search NASA⌕ Search

DOE OSTI · 1300451

Materials Data on Na3SnPCO7 by Materials Project

Abstract

Na3SnCPO7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent PO4 tetrahedra and edges with two equivalent NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.29–2.65 Å. In the second Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.40–2.62 Å. In the third Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.76 Å. Sn2+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Sn–O bond distances ranging from 2.25–2.51 Å. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.29 Å) and two longer (1.31 Å) C–O bond length. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 29–65°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Na1+ and one C4+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, one Sn2+, and one C4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one Sn2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Na1+, one Sn2+, and one C4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Sn2+, and one P5+ atom.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-07-15. Materials Data on Na3SnPCO7 by Materials Project. https://doi.org/10.17188/1300451

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

36 MATERIALS SCIENCE↗